1. Technical Field
The present invention relates to an engine exhaust treatment device, and in detail, relates to an engine exhaust treatment device capable of combusting PM accumulated in a DPF or activating an exhaust purification catalyst even immediately after engine startup or at the time of light load operation.
2. Background Art
Conventionally, there has been an engine exhaust treatment device for generating a combustible gas by a combustible gas generator, emitting this combustible gas to an exhaust passage from a combustible gas emission port, catalyst-combusting this combustible gas by a combustion catalyst, increasing a temperature of an exhaust by heat of the catalyst combustion, and combusting and removing PM accumulated in a DPF which is arranged on a downstream of the combustion catalyst, or activating an exhaust purification catalyst arranged on a downstream of the combustion catalyst, for example, refer to Japanese Patent Laid-open Publication No. 2007-71034 (refer to FIG. 1).
According to this type of exhaust treatment device, there is an advantage that even in a case where the temperature of the exhaust is relatively low, the temperature of the exhaust can be increased with the combustible gas by the catalyst-combustion.
However, this conventional technique does not include a combustion unit of the combustible gas other than the combustion catalyst, so that there is a problem.